Sewing machine thread cutting mechanism



Nov. 5, 1963 H. M. HORNBERGER, SR 3,109,399

SEWING MACHINE THREAD CUTTING MECHANISM 5 Sheets-Sheet 1 Filed Aug. 22. 1961 LI F 6 HE Ira TIE- INVENTOR: 1% 171.11 1 5 ev g??? r ORN QM l Nov. 5, 1963 H. M. HORNBERGER, sR 3,109,399

SEWING MACHINE THREAD CUTTING MECHANISM Filed Aug. 22, 1961 Sheets-Sheet 2 a in E my 6 ilgyl L5 8 A 4L3 E 5/ MJ/ 5'. /06 {I i J INVENTOR:

E, lfarlymfiornber e? W iW Nov. 5, 1963 H. M. HORNBERGER, SR 3,109,399

SEWING MACHINE THREAD cu'rwmc MECHANISM Filed Aug. 22, 1961 r 5 Sheets-Sheet 5 TILE- c5 INVENTOR Nov. 5, 1963 H. M. HORNBERGER, SR 3,109,399

SEWING MACHINE THREAD CUTTING MECHANISM Filed Aug. 22, 1961 5 Sheets-Sheet 4 TIE- ll- 88 ml l llll'lllll INVENTOR:

Harry DY. Hornbep/ger, 51'.

United States Patent 3,109,399 SEWING MACHINE THREAD CUTTING MECHANISM Harry M. Hornherger, Sn, Mohnton, Pa., assignor, by mesne assignments, to Merrow Machine Company,

Hartford, Conn, a corporation of Connecticut Filed Aug. 22, 1961, Ser. No. 133,267

4 Claims. (Cl. 112-252) This invention relates to sewing machines and more particularly concerns a unique sewing machine having special means for cutting, trimming and disposing of surplus thread from the articles operated on by the machine.

Sewing machines have heretofore been used in the practice of closing the open ends of the toe portions of knitted stockings and socks by a straight line of stitches. The prior art procedure of sewing shut the toe ends, one after another, results in the extension of the sewing thread from one hosiery article to another in progressive order. These continuous thread extensions are later removed by the operator with a pair of scissors. This thread removing operation is time consuming and adds to the production cost.

One object of the present invention is to provide a novel sewing machine in which there is combined with usual means for stitching shut the toe end portions of the knitted stockings and socks, special means for cutting off the surplus stitching thread at both ends of the stitched portions of the knitted stockings and socks, as well as suction means for automatically removing the cut-off thread to a remote waste container.

Another object is to provide a sewing machine comprising a sewing needle, a mechanism for operating said needle, means for feeding a work piece to the needle so as to effect a stitching operation, and a surplus thread removing cutter unit connected with said feeding means and arranged transversely of the path of travel of the work piece beyond the location where the stitching operation is performed.

A further object is to provide such a sewing machine having certain structural and functional features of advantage over the similar sewing machines of the prior art.

Another object is to provide such a sewing machine having the feed dogs of the work feed mechanism operable in the usual manner, and in which novel thread cutting means is operatively associated with the feed dog operating mechanism.

It is also an object to provide a surplus thread removing structure for a sewing machine having a feed dog mechanism, which structure comprises a support, a work receiving plate pivotally mounted on said support, a surplus thread removing cutter unit mounted on said support, a suction nozzle mounted on said support in adjacent relation with said unit, and means on said unit for effecting operating connection thereof with the feed dog mechanism of the sewing machine to which the structure is applied.

An additional object is to provide such a sewing machine that is structurally and functionally simple, practical, effective and efficient in its operation, strong and reliable in use, useful for stitching articles of many types and sizes, relatively inexpensive to manufacture, and otherwise well adapted for the purpose for which the same is intended.

With these and other objects in View, which will become more readily apparent from the following detailed description of one practical and illustrative embodiment of the improvements here involved, my invention comprises the novel sewing machine, sewing machine structure, elements, features of construction and arrangement of parts in cooperative relationship, as more particularly indicated and defined by the hereto appended claims.

3,109,399 Patented Nov. 5, 1963 In the accompanying drawings:

FIGURE 1 is a top plan view of a sewing machine embodying one form of the present invention;

FIG. 2 is a front elevation of the left hand end or sewing head portion of the structure illustrated in FIG. 1;

FIG. 3 is a top edge view of a certain motion transmitting element which forms part of the present invention, as it appears when removed from the machine;

FIG. 4 is a front elevation of the element illustrated in FIG. 3;

FIG. 5 is a front edge elevational view of the motion transmitting element illustrated in FIGS. 3 and 4;

FIG. 6 is an enlarged end elevation of a portion of the sewing head, the work plate and certain other parts being removed;

FIG. 7 is a horizontal section taken substantially as indicated by the 7-7 of FIG. 6;

FIG. 8 is a vertical sectional view taken substantially as indicated by the arrows 8-8 of FIG. 7;

FIG. 9 is a detail perspective view of a cutter guide element which forms part of my invention, as it appears when removed from the upper end portion of the structure illustrated in FIG. 8;

FIG. 10 is a detail perspective view of an actuator element which forms part of my invention;

FIG. 11 is an enlarged plan view of a certain sewing machine structure including the work plate, cutter unit, etc. of the present invention, the needle plate and feed dogs of the sewing machine being illustrated by broken lines;

FIG. 12 is an elevational view of FIG. 11, and shows by broken lines a work piece thereon;

FIG. 13 is a partial vertical transverse section, taken substantially along the line 1313 of FIG. 11;

FIG. 14 is an enlarged detail end elevation of the sewing head, parts being omitted to illustrate portions of the operating mechanism;

FIG. 15 is a schematic plan view illustrating the prior art manner in which the toe portions of knitted stockings and socks are connected together by a thread extension from one hosiery article to another in progressive order; and

FIG. 16 is a schematic plan view illustrating the man net in which a hosiery article has its toe end closed by the sewing machine of the present invention, the surplus thread removed during the stitching operation being shown by broken lines.

It will facilitate an understanding of my invention to first briefly consider some of the more important aspects and phases thereof so that these may be kept in mind when subsequently reading the detailed description of the embodiment thereof as illustrated by the drawings.

Accordingly, it is noted that, for purposes of exemplification, or illustration, the invention is herein shown applied to a standard or conventional sewing machine of the type manufactured by The Merrow Machine Company, of Hartford, Connecticut. The construction and operation of such a conventional sewing machine is disclosed in a publication entitled Instructions for Setting Up 'and Operating Class M Merrow Machines, which publication was copyrighted in 1955 by the Merrow Machine Company.

The said Class M Merrow machines are adapted to overseam and trim simultaneously and form one of the following stitch formations; a one-thread overseam; a two-thread overseam or finish; a three-thread overseam or finish; or a three-thread tight needle thread seam.

Although, in the instant case, the invention is shown embodied in said conventional sewing machine which is adapted to form a two-thread overseam or finish thread operation, it is to be understood that the invention is not limited in its application to the details of construction 3 and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

In the accompanying drawings only those parts of the conventional above identified sewing machine are shown, indicated, and will be described, as are deemed necessary to an understanding of the present invention. For further information concerning the construction and operation of the said above identified sewing machine, reference may be had to the heretofore mentioned publication, said machine, thepatents issued thereon, or other literature .and publications made available by the manufacturer of said sewing machine with respect thereto.

Those parts of the said conventional sewing machine will first be described with which the present invention is cooperatively associated and this will be followed by a detailed description of my improvements and the'manner in which they effect a novel sewing machine and surplus thread removing structure for such a machine.

Referring to the drawings, there is shown in FIGS. 1,

- 2, 6 and 14, a sewing machine 1 of the conventional type heretofore mentioned, said sewing machine having a base 2 by which the machine is secured to suitable supporting means, such as a table or the like (not shown).

The sewing. machine'l has a frame or housing 3, which at one end carries or supports the usual sewing head, generally indicated at 4.

The sewing head 4 includes a needle carrier assembly 5, aneedle plate 6, a plurality of feed dogs which are more particularly identified and described hereinafter, a presser foot assembly 9, a fabric cutter mechanism 10, a fabric guard 11, a dust shield 12, a work plate 13, and operating mechanism to be hereinafter described.

A drive shaft 15 is arranged lengthwise of the sewing machine frame 3 and projects a suitable distance beyond each end thereof. I I

The end portion of the drive shaft 15 which projects beyond theend of the frame 3 opposite to the end having the sewing head 4, is provided with a hand wheel 16.

The hand wheel 16 has an extension integral therewith formed with an annular V-shaped groove 17 arranged to receive a drive belt 18, FIG. 1, which is operatively connected in a well known manner to a source of power (not shown) for imparting rotation to the drive shaft 15 in the direction of the arrow 19.

The needle plate 6, which is fixedly mounted on the sewing head 4 in the usual manner, is provided with a plushown are the usual loopers which are arranged to cooperate with the needles 32 to form the stitches.

In sewing machines of the type herein shown and described, there are two sets of feed dogs, having the usual serrations thereon corresponding substantially in size and form with the needle plate serrations 28 and 29.

One set of feed dogs include an elongated feed dog 35 located within the forward portion of the aperture 21, and a feed dog 36 located within the aperture 22.

The other set of feed dogs include a relatively short feed dog 37 located within the rear portion of the aperture 21, a feed dog 38 located within the aperture 23, and a feed dog 39 located in the notch 31.

The :feed dogs 35 and 36 have a forked arm 46 depending therefrom by which these feed dogs are connected, as indicated at 41, to the forward portion of a feed carrier member 42, as shown in FIG. 14.

in a similar manner the feed dogs 37, 38 and 39 have a forked arm 44 depending therefrom, by which said feed dogs are connected, as indicated at 45, to the forward portion 46 of a second feed carrier member 47.

The two feed carrier members 42 and 47 are operatively connected in well known manner to a feed carrier link 48 ral'ity of elongated apertures 21, 22 and 23, as clearly 7 distance from the aperture 21 by a web 26.

The aperture 23 is arranged in parallel spaced relationship with respect to the aperture 21, and is located in the rear portion of the needle plate 6 in offset relation with respect to the aperture 22, said aperture 23 being spaced a closer distance from the aperture 21 than is the distance separating the aperture 22 fromthe aperture 21, as defined bythe web 27.

Upstanding. teeth or serrations 28 and 29 are formed on the forward portion of the upper surface of the needle plate 6 at opposite sidesof the aperture 21.

The needle plate :6 is also provided with an opening 31 in which the sewing needles 22 operate in well known manner from the needle carrier assembly 5. Also not having an eccentric 49 mounted on the drive shaft 15 in the manner illustrated in FIG. .14. As shown also in FIG. 6 the feed carrier member 47 is operatively connected, as indicated at 54}, to a second feed carrier link 51, having an eccentric 52 mounted on the end of the drive shaft 15 heretofore referred to.

It will be understood that rotation of the drive shaft 15 in the direction of the arrow 19, FIG. 1, actuates the feed dog operating mechanism above described, to impart to said feed dogs the customary motions by which the work pieces are advanced in a direction lengthwise of the needle plate 6 during the stitching operation. In order to effect such motions to the feed dogs, the portion 46 of the feed carrier member 47 moves upwardly and downwardly and rear-wardly and forwardly in well known manner, about a pivot block 53, FIG. 14.

As shown in FIG. 6, the presser foot assembly 9 comprises a presser foot 56 pivota-lly connected to one end portion of an arm 57, as indicated at '58, whereby the presser foot is tiltable in upward and downward directions.

The end of the arm 57 opposite to the end carrying the presser foot 56 is hingedly connected, as indicated at 5-9, to a block 60 mounted on the frame 3 so that said presser foot arm and the presser foot 56 carried thereby are swingable as a unit in directions outwardly and inwardly, or away from and toward the sewing head 4.

The presser foot arm 57 is provided with a notch 62 in which is seated a latch member 63 having an operating lever 64 arranged to move the latch into and out of engagement with the notch ,in a well known manner, and thereby retain the presser foot in an assembled relationship with the needle plate 6.

The presser foot 56' is normally arranged directly over that the sewing thread 69 would extend from the toe portion of one sock to the toe portion of the next sock, the sewing operationsare all in accordance with the prior art practice as accomplished with the Merrow sewing machine above identified and having the various elements and parts heretofore described.

The present invention provides improved means for eliminating the connecting thread 69 between the stitched socks as carried out in accordance with the prior art practice, by making the toe closing stitching operation a separate procedure for each sock, so that there are no connecting threads between the successive socks operated on by the sewing machine. To this end the structural and functional means of the present invention are cooperatively associated with certain heretofore described mechanisms in the manner about to be described.

The work plate 13 is ilocated at the end of the sewing machine having the sewing head 4, and overlies the operating mechanism for the feed dogs and associated parts as heretofore described.

The work plate 13 comprises an elongated body, preferably formed of sheet metal of suitable thickness, said body having a front work receiving and supporting portion 72, which extends forwardly beyond the front face of the sewing machine frame 3 a suitable distance and terminates in a forward edge '73, as shown in FIG. 1.

Extending rearwardly from the forward edge 73 of the front portion 72, of the work plate 13, and arranged subis formed in the body of the work plate inwardly of the side edge portion 75. The purpose of this notch 76 is to provide an opening for parts of the sewing head elements, such as the feed dogs, the needle plate 6, and

the presser foot 56.

Beyond the notch 76, the body of the work plate 13 extends rearwa-rdly a suitable distance to provide a rear portion 78, generally arcuate in form.

Fixedly mounted on the end of the frame 3, by means of screws 79 and arranged beneath the portion 78 of the work plate 13, is a bracket 80, having a vertical opening 81 formed therein for a headed stud 82 carried by the portion 78 of the work plate 13 and depending therefrom in the manner shown in FIG. 12, said stud being held in place in the bracket 80 by a set screw 83.

The construction and arrangement of the parts is such that, due to the manner in which the work plate 13 is pivotally connected to the fixed bracket 80, by the stud '82, said work plate is movable in well known manner in a generally horizontal path from the position shown by full lines to the position shown by broken lines in FIG. 1. This swinging movement of the work plate 13 is provided so that the operator can readily gain access to the portions of the mechanism located underneath the work plate for the purpose of adjustin cleaning and repairing such mechanism.

For the purpose of retaining the work plate 13 in a fixed position with respect to the stitch forming elements of the sewing machine, an upwardly projecting spring pressed plunger or detent 70 is mounted in the bracket 86 and arranged in offset relation with respect to the stud opening 81 thereof, in the manner shown in FfGS. 7, 11 and 12, for engagement in a recess or cavity 71 formed in the underside of the work plate 13. It will be understood that when the plunger or detent 70 is disposed in the recess or cavity 71, the work plate 13 will remain in fixed position relative to the sewing head 4. However, when it is desired to expose the mechanism of the sewing head located underneath the Work plate 13, the operator swings the work plate in a direction toward the position shown by broken lines in FIG. 1. This action breaks the connection provided by the positioning of the plunger or detent 70 in the recess or cavity 71, thereby permitting the tip of the plunger or detent to move freely along the under surface of the work plate 13. To prevent overtravel of the work plate 13 in a direction opposite to the direction above described, said plate is provided with a depending pin 77 arranged to abut against a base 84.

As shown in FIGS. 6 and 12, the base 84 is attached, as indicated at 86, to a face 87 of the bracket 80, to provide a support for a cutter head unit 85.

As shown in FIGS. 6, 7, 8, 9, 11 and 12, the cutter head unit comprises a plate 88 mounted on a face 89 of the base 84 and so arranged thereon that said plate 88 extends in transverse direction substantially at right angles with the line of travel of the work pieces.

At its inner end portion, the plate 88 is provided lengthwise thereof with a series of upstanding teeth 91 having side cutting edges to provide the fixed element of a thread cutter. The upper tip ends of the teeth 91 are located above the needle plate 6, as shown in FIG. 6.

Secured to the front face of the plate 88 by screws 94, is a bearing frame 92 (FIGS. 8 and 12), having a longitudinally extending V-shaped rib 93 arranged in spaced relation with the front face of the plate or fixed cutter blade 88.

A movable cutter blade 95 having a V-shaped groove 96 formed lengthwise thereof to receive the rib 93 of the bearing frame 92, is provided with a series of upstanding teeth 97. The teeth are generally similar in form to the teeth 91 of the fixed blade 88, and have side cutting edges to provide the movable element of the thread cutter by means of which loose ends of thread extending from the work pieces are sheared off, during operation of the sewing machine in the manner to be hereinafter more fully described.

In addition to the groove 96, the body of the movable thread cutter blade 55 is provided with a notch or recess 9 8 (see FIG. 8).

Since the cutter head unit 85 is fixedly mounted on the bracket 3t), and since the teeth of the cutter blades thereof project above the work plate 13, a notch 99' is formed in said work plate in which the cutter blades are disposed, as clearly shown in FIG. 11.

Below the portion of the bearing frame 92 having the rib 93, the body of said bearing frame is formed with an aperture 100. The purpose of this aperture 180 is to provide an opening in the bearing frame 92 through which extends a finger 102 of a motion transmitting element 104, said finger 102 being mounted in the notch 98 of the movable thread cutter blade 95 heretofore described (see FIG. 8).

The motion transmitting element 104 is pivotally mounted by means of a pivot element 105 on a bracket 186 carried by the sewing machine frame 3, said bracket being secured to said frame by means of screws or bolts 107 (FIG. 8).

The motion transmitting element 104 is provided with a forked end portion 108 having a slot 109 in the extremity thereof in which is mounted a lug 110 of an actuator element 111.

The actuator element 111 is fixedly mounted on the part 46 of the feed carrier member 47 by means of the connector element 45 heretofore described (see FIG. 14).

Since the actuator 111 is directly connected by means of the element 45 to the mechanism provided for imparting the customary feed dog motions, said actuator 111 will transmit, through its lug 110, oscillatory motions to the element 104. The motions thus transmitted by the actuator 111 to the element 104 are then transmitted by the finger 182 of the element IM to the movable cutter blade 95. In this manner the movable cutter blade 95 is reciprocated with respect to the fixed cutter blade 88 to produce the usual shearing action.

When a work piece, such as a knitted sock 115, having an open toe portion, is placed in the sewing machine for the purpose of closing the open toe portion by a straight line of stitches 11 6, loose threads 117 and 118 are produced at the front and rear ends respectively of the stitched portion of the socks as shown in FIG. 16.

The broken lines 120 shown in FIG. 16 illustrate the toe extension portion of the knitted. sock which is cut off by the fabric cutter mechanism 110 which forms a conventional part of the sewing machine. This cutting action takes place simultaneously with the straight line stitching operation.

As the work piece advances beyond the needles 32 and the surplus thread 117 reaches the vicinity of the cutter head unit 85, suction from the nozzle 121 of a suction pipe 122 draws the free end portion of the thread, as indicated by the dot and dash lines in FIG. 12, through the cutter blades 88 and 95, for, severance there-by. The severed thread is then drawn by suction through the pipe 122 and conducted thereby to a usual remote waste container (not shown). The suction means whereby suction is created in the pipe 122 may be of any approved 7 well known prior art type, such as used for a surplus thread removing purpose in connection with sewing or other similar machines.

As shown inFIGS. 6 ,7, 11 and 12, the pipe 122 is provided with a sewing plate 127 which is fixed to the bracket 86 by means of screws 1'28, whereby said pipe is supported from the bracket 80.

In order to steady the nozzle 121 of the pipe 122 against machine vibrations, a support element 123 is mounted on the bracket 89 and arranged in contacting relation with the exterior surface of the nozzle.

A screw 124 carried by the work .plate 13 and located directly above the support element 123 in the manner illustrated in FIG. 11, has its lower end arranged for contacting engagement with the upper surface of the element 123, thereby to exert steady pressure against the nozzle 121 when the work plate 13 has been swung into the position shown in FIG. 11.

As the work piece moves past the cutter head unit 85, the trailing thread 118, as it is severed by the cutter blades, is drawn by suction into the nozzle 121 of the suction pipe 122 and conducted thereby to the remote waste container heretofore referred to.

In thisrnanner surplus threads at the ends of sock having their open toe ends closed by a straight line of stitches, are quickly removed from the socks, thereby reducing the operating time heretofore required.

As shown in FIGS. 12 and 13, the upper surface of the portion of the work plate 13 in the vicinity of the cutter head unit 85 is raised, as indicated at 125, so that the fabric of the work pieces being operated on will be guided 7 over the cutter blades and will not be caught therein.

As indicated at 65 in FIG. 13, the presser foot 56 is provided on its underside with a longitudinally extending groove which is for the purpose of receiving and guiding in a substantially straight line, the thread thickened end portion 116 of the sock that is closed by the stitching 1 and advantages of my invention.

I claim:

1. A sewing machine comprising: a sewing needle; a mechanism for operating said needle; means for feeding a work piece to the needle so as to effect a stitching operation; a surplus thread removing cutter unit arranged transversely of the path of travel of the work piece beyond the location where the stitching operation is performed, which unit includes a fixedly mounted toothed blade and a cooperating reciprocably movable toothed blade provided with a recess; a motion transmitting lever pivotally mounted adjacent to said movable blade which lever has a finger-like member arranged to extend into said recess and a portion provided with a slot; and a cutter unit actuating element fixedly mounted on said workpiece feeding means so as to extend in substantially right-angular relation with said motion transmitting lever, which element has a projection arranged to extend into the slot of said motion transmitting lever.

2. A sewing machine in accordance with claim 1; which includes a horizontally arranged pivotally mounted work supporting plate, and detent means for maintaining said plate in a selected one of a plurality of positions to which it is swingable about its pivot.

3. A sewing machine in accordance with claim 1; which includes a horizontally arranged work supporting plate having a notch through which the teeth of the cutter unit are arranged to extend and which work supporting plate has a raised portion adjacent to said notch to effect guiding over said raised portion of the work piece in such manner that the latter will not be caught in said cutter unit teeth.

4.' A sewing machine in accordance with claim 1; wherein the work piece feeding means includes a presser foot having a longitudinal guide groove arranged in the under surface thereof for effecting straight'line movement therealong of the thickened stitched portion of the work piece towards the cutter unit.

References Cited in the file of this patent UNITED STATES PATENTS 1,568,986 Merrow Jan. 12, 1926 1,950,885 Gross Mar. 13, 1934 2,288,051 Voight June 30, 1942 2,356,378 Capolupo Aug. 22, 1944 2,398,697 Colegrove Apr. 16, 1946 2,712,805 Peterson et a1. July 12, 1955 3,058,438 Russell et al. Oct. 16, 1962 

1. A SEWING MACHINE COMPRISING: A SEWING NEEDLE; A MECHANISM FOR OPERATING SAID NEEDLE; MEANS FOR FEEDING A WORK PIECE TO THE NEEDLE SO AS TO EFFECT A STITCHING OPERATION; A SURPLUS THREAD REMOVING CUTTER UNIT ARRANGED TRANSVERSELY OF THE PATH OF TRAVEL OF THE WORK PIECE BEYOND THE LOCATION WHERE THE STITCHING OPERATION IS PERFORMED, WHICH UNIT INCLUDES A FIXEDLY MOUNTED TOOTHED BLADE AND A COOPERATING RECIPROCABLY MOVABLE TOOTHED BLADE PROVIDED WITH A RECESS; A MOTION TRANSMITTING LEVER PIVOTALLY MOUNTED ADJACENT TO SAID MOVABLE BLADE WHICH LEVER HAS A FINGER-LIKE MEMBER ARRANGED TO EXTEND INTO SAID RECESS AND A PORTION PROVIDED WITH A SLOT; AND A CUTTER UNIT ACTUATING ELEMENT FIXEDLY MOUNTED ON SAID WORK PIECE FEEDING MEANS SO AS TO EXTEND IN SUBSTANTIALLY RIGHT-ANGULAR RELATION WITH SAID MOTION TRANSMITTING LEVER, WHICH ELEMENT HAS A PROJECTION ARRANGED TO EXTEND INTO THE SLOT OF SAID MOTION TRANSMITTING LEVER. 